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a497ee34 | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
ea25da48 PV |
2 | /* |
3 | * Header file for the BFQ I/O scheduler: data structures and | |
4 | * prototypes of interface functions among BFQ components. | |
ea25da48 PV |
5 | */ |
6 | #ifndef _BFQ_H | |
7 | #define _BFQ_H | |
8 | ||
9 | #include <linux/blktrace_api.h> | |
10 | #include <linux/hrtimer.h> | |
11 | #include <linux/blk-cgroup.h> | |
12 | ||
1d156646 TH |
13 | #include "blk-cgroup-rwstat.h" |
14 | ||
ea25da48 PV |
15 | #define BFQ_IOPRIO_CLASSES 3 |
16 | #define BFQ_CL_IDLE_TIMEOUT (HZ/5) | |
17 | ||
18 | #define BFQ_MIN_WEIGHT 1 | |
19 | #define BFQ_MAX_WEIGHT 1000 | |
20 | #define BFQ_WEIGHT_CONVERSION_COEFF 10 | |
21 | ||
22 | #define BFQ_DEFAULT_QUEUE_IOPRIO 4 | |
23 | ||
24 | #define BFQ_WEIGHT_LEGACY_DFL 100 | |
25 | #define BFQ_DEFAULT_GRP_IOPRIO 0 | |
26 | #define BFQ_DEFAULT_GRP_CLASS IOPRIO_CLASS_BE | |
27 | ||
582f04e1 | 28 | #define MAX_BFQQ_NAME_LENGTH 16 |
1e66413c | 29 | |
ea25da48 PV |
30 | /* |
31 | * Soft real-time applications are extremely more latency sensitive | |
32 | * than interactive ones. Over-raise the weight of the former to | |
33 | * privilege them against the latter. | |
34 | */ | |
35 | #define BFQ_SOFTRT_WEIGHT_FACTOR 100 | |
36 | ||
37 | struct bfq_entity; | |
38 | ||
39 | /** | |
40 | * struct bfq_service_tree - per ioprio_class service tree. | |
41 | * | |
42 | * Each service tree represents a B-WF2Q+ scheduler on its own. Each | |
43 | * ioprio_class has its own independent scheduler, and so its own | |
44 | * bfq_service_tree. All the fields are protected by the queue lock | |
45 | * of the containing bfqd. | |
46 | */ | |
47 | struct bfq_service_tree { | |
48 | /* tree for active entities (i.e., those backlogged) */ | |
49 | struct rb_root active; | |
38c91407 | 50 | /* tree for idle entities (i.e., not backlogged, with V < F_i)*/ |
ea25da48 PV |
51 | struct rb_root idle; |
52 | ||
53 | /* idle entity with minimum F_i */ | |
54 | struct bfq_entity *first_idle; | |
55 | /* idle entity with maximum F_i */ | |
56 | struct bfq_entity *last_idle; | |
57 | ||
58 | /* scheduler virtual time */ | |
59 | u64 vtime; | |
60 | /* scheduler weight sum; active and idle entities contribute to it */ | |
61 | unsigned long wsum; | |
62 | }; | |
63 | ||
64 | /** | |
65 | * struct bfq_sched_data - multi-class scheduler. | |
66 | * | |
67 | * bfq_sched_data is the basic scheduler queue. It supports three | |
68 | * ioprio_classes, and can be used either as a toplevel queue or as an | |
46d556e6 | 69 | * intermediate queue in a hierarchical setup. |
ea25da48 PV |
70 | * |
71 | * The supported ioprio_classes are the same as in CFQ, in descending | |
72 | * priority order, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE. | |
73 | * Requests from higher priority queues are served before all the | |
74 | * requests from lower priority queues; among requests of the same | |
75 | * queue requests are served according to B-WF2Q+. | |
46d556e6 PV |
76 | * |
77 | * The schedule is implemented by the service trees, plus the field | |
78 | * @next_in_service, which points to the entity on the active trees | |
79 | * that will be served next, if 1) no changes in the schedule occurs | |
80 | * before the current in-service entity is expired, 2) the in-service | |
81 | * queue becomes idle when it expires, and 3) if the entity pointed by | |
82 | * in_service_entity is not a queue, then the in-service child entity | |
83 | * of the entity pointed by in_service_entity becomes idle on | |
84 | * expiration. This peculiar definition allows for the following | |
85 | * optimization, not yet exploited: while a given entity is still in | |
86 | * service, we already know which is the best candidate for next | |
636b8fe8 | 87 | * service among the other active entities in the same parent |
46d556e6 PV |
88 | * entity. We can then quickly compare the timestamps of the |
89 | * in-service entity with those of such best candidate. | |
90 | * | |
91 | * All fields are protected by the lock of the containing bfqd. | |
ea25da48 PV |
92 | */ |
93 | struct bfq_sched_data { | |
94 | /* entity in service */ | |
95 | struct bfq_entity *in_service_entity; | |
96 | /* head-of-line entity (see comments above) */ | |
97 | struct bfq_entity *next_in_service; | |
98 | /* array of service trees, one per ioprio_class */ | |
99 | struct bfq_service_tree service_tree[BFQ_IOPRIO_CLASSES]; | |
100 | /* last time CLASS_IDLE was served */ | |
101 | unsigned long bfq_class_idle_last_service; | |
102 | ||
103 | }; | |
104 | ||
105 | /** | |
2d29c9f8 | 106 | * struct bfq_weight_counter - counter of the number of all active queues |
ea25da48 PV |
107 | * with a given weight. |
108 | */ | |
109 | struct bfq_weight_counter { | |
2d29c9f8 FM |
110 | unsigned int weight; /* weight of the queues this counter refers to */ |
111 | unsigned int num_active; /* nr of active queues with this weight */ | |
ea25da48 | 112 | /* |
2d29c9f8 | 113 | * Weights tree member (see bfq_data's @queue_weights_tree) |
ea25da48 PV |
114 | */ |
115 | struct rb_node weights_node; | |
116 | }; | |
117 | ||
118 | /** | |
119 | * struct bfq_entity - schedulable entity. | |
120 | * | |
121 | * A bfq_entity is used to represent either a bfq_queue (leaf node in the | |
122 | * cgroup hierarchy) or a bfq_group into the upper level scheduler. Each | |
123 | * entity belongs to the sched_data of the parent group in the cgroup | |
124 | * hierarchy. Non-leaf entities have also their own sched_data, stored | |
125 | * in @my_sched_data. | |
126 | * | |
127 | * Each entity stores independently its priority values; this would | |
128 | * allow different weights on different devices, but this | |
129 | * functionality is not exported to userspace by now. Priorities and | |
130 | * weights are updated lazily, first storing the new values into the | |
131 | * new_* fields, then setting the @prio_changed flag. As soon as | |
132 | * there is a transition in the entity state that allows the priority | |
133 | * update to take place the effective and the requested priority | |
134 | * values are synchronized. | |
135 | * | |
136 | * Unless cgroups are used, the weight value is calculated from the | |
137 | * ioprio to export the same interface as CFQ. When dealing with | |
636b8fe8 | 138 | * "well-behaved" queues (i.e., queues that do not spend too much |
ea25da48 PV |
139 | * time to consume their budget and have true sequential behavior, and |
140 | * when there are no external factors breaking anticipation) the | |
141 | * relative weights at each level of the cgroups hierarchy should be | |
142 | * guaranteed. All the fields are protected by the queue lock of the | |
143 | * containing bfqd. | |
144 | */ | |
145 | struct bfq_entity { | |
146 | /* service_tree member */ | |
147 | struct rb_node rb_node; | |
ea25da48 PV |
148 | |
149 | /* | |
150 | * Flag, true if the entity is on a tree (either the active or | |
151 | * the idle one of its service_tree) or is in service. | |
152 | */ | |
33a16a98 | 153 | bool on_st_or_in_serv; |
ea25da48 PV |
154 | |
155 | /* B-WF2Q+ start and finish timestamps [sectors/weight] */ | |
156 | u64 start, finish; | |
157 | ||
158 | /* tree the entity is enqueued into; %NULL if not on a tree */ | |
159 | struct rb_root *tree; | |
160 | ||
161 | /* | |
162 | * minimum start time of the (active) subtree rooted at this | |
163 | * entity; used for O(log N) lookups into active trees | |
164 | */ | |
165 | u64 min_start; | |
166 | ||
167 | /* amount of service received during the last service slot */ | |
168 | int service; | |
169 | ||
170 | /* budget, used also to calculate F_i: F_i = S_i + @budget / @weight */ | |
171 | int budget; | |
172 | ||
98f04499 JK |
173 | /* Number of requests allocated in the subtree of this entity */ |
174 | int allocated; | |
175 | ||
795fe54c FZ |
176 | /* device weight, if non-zero, it overrides the default weight of |
177 | * bfq_group_data */ | |
178 | int dev_weight; | |
ea25da48 PV |
179 | /* weight of the queue */ |
180 | int weight; | |
181 | /* next weight if a change is in progress */ | |
182 | int new_weight; | |
183 | ||
184 | /* original weight, used to implement weight boosting */ | |
185 | int orig_weight; | |
186 | ||
187 | /* parent entity, for hierarchical scheduling */ | |
188 | struct bfq_entity *parent; | |
189 | ||
190 | /* | |
191 | * For non-leaf nodes in the hierarchy, the associated | |
192 | * scheduler queue, %NULL on leaf nodes. | |
193 | */ | |
194 | struct bfq_sched_data *my_sched_data; | |
195 | /* the scheduler queue this entity belongs to */ | |
196 | struct bfq_sched_data *sched_data; | |
197 | ||
198 | /* flag, set to request a weight, ioprio or ioprio_class change */ | |
199 | int prio_changed; | |
ba7aeae5 PV |
200 | |
201 | /* flag, set if the entity is counted in groups_with_pending_reqs */ | |
202 | bool in_groups_with_pending_reqs; | |
430a67f9 PV |
203 | |
204 | /* last child queue of entity created (for non-leaf entities) */ | |
205 | struct bfq_queue *last_bfqq_created; | |
ea25da48 PV |
206 | }; |
207 | ||
208 | struct bfq_group; | |
209 | ||
210 | /** | |
211 | * struct bfq_ttime - per process thinktime stats. | |
212 | */ | |
213 | struct bfq_ttime { | |
214 | /* completion time of the last request */ | |
215 | u64 last_end_request; | |
216 | ||
217 | /* total process thinktime */ | |
218 | u64 ttime_total; | |
219 | /* number of thinktime samples */ | |
220 | unsigned long ttime_samples; | |
221 | /* average process thinktime */ | |
222 | u64 ttime_mean; | |
223 | }; | |
224 | ||
225 | /** | |
226 | * struct bfq_queue - leaf schedulable entity. | |
227 | * | |
228 | * A bfq_queue is a leaf request queue; it can be associated with an | |
229 | * io_context or more, if it is async or shared between cooperating | |
230 | * processes. @cgroup holds a reference to the cgroup, to be sure that it | |
231 | * does not disappear while a bfqq still references it (mostly to avoid | |
232 | * races between request issuing and task migration followed by cgroup | |
233 | * destruction). | |
234 | * All the fields are protected by the queue lock of the containing bfqd. | |
235 | */ | |
236 | struct bfq_queue { | |
237 | /* reference counter */ | |
238 | int ref; | |
430a67f9 PV |
239 | /* counter of references from other queues for delayed stable merge */ |
240 | int stable_ref; | |
ea25da48 PV |
241 | /* parent bfq_data */ |
242 | struct bfq_data *bfqd; | |
243 | ||
244 | /* current ioprio and ioprio class */ | |
245 | unsigned short ioprio, ioprio_class; | |
246 | /* next ioprio and ioprio class if a change is in progress */ | |
247 | unsigned short new_ioprio, new_ioprio_class; | |
248 | ||
2341d662 PV |
249 | /* last total-service-time sample, see bfq_update_inject_limit() */ |
250 | u64 last_serv_time_ns; | |
251 | /* limit for request injection */ | |
252 | unsigned int inject_limit; | |
253 | /* last time the inject limit has been decreased, in jiffies */ | |
254 | unsigned long decrease_time_jif; | |
255 | ||
ea25da48 PV |
256 | /* |
257 | * Shared bfq_queue if queue is cooperating with one or more | |
258 | * other queues. | |
259 | */ | |
260 | struct bfq_queue *new_bfqq; | |
261 | /* request-position tree member (see bfq_group's @rq_pos_tree) */ | |
262 | struct rb_node pos_node; | |
263 | /* request-position tree root (see bfq_group's @rq_pos_tree) */ | |
264 | struct rb_root *pos_root; | |
265 | ||
266 | /* sorted list of pending requests */ | |
267 | struct rb_root sort_list; | |
268 | /* if fifo isn't expired, next request to serve */ | |
269 | struct request *next_rq; | |
270 | /* number of sync and async requests queued */ | |
271 | int queued[2]; | |
ea25da48 PV |
272 | /* number of pending metadata requests */ |
273 | int meta_pending; | |
274 | /* fifo list of requests in sort_list */ | |
275 | struct list_head fifo; | |
276 | ||
277 | /* entity representing this queue in the scheduler */ | |
278 | struct bfq_entity entity; | |
279 | ||
2d29c9f8 FM |
280 | /* pointer to the weight counter associated with this entity */ |
281 | struct bfq_weight_counter *weight_counter; | |
282 | ||
ea25da48 PV |
283 | /* maximum budget allowed from the feedback mechanism */ |
284 | int max_budget; | |
285 | /* budget expiration (in jiffies) */ | |
286 | unsigned long budget_timeout; | |
287 | ||
288 | /* number of requests on the dispatch list or inside driver */ | |
289 | int dispatched; | |
290 | ||
291 | /* status flags */ | |
292 | unsigned long flags; | |
293 | ||
294 | /* node for active/idle bfqq list inside parent bfqd */ | |
295 | struct list_head bfqq_list; | |
296 | ||
297 | /* associated @bfq_ttime struct */ | |
298 | struct bfq_ttime ttime; | |
299 | ||
eb2fd80f PV |
300 | /* when bfqq started to do I/O within the last observation window */ |
301 | u64 io_start_time; | |
302 | /* how long bfqq has remained empty during the last observ. window */ | |
303 | u64 tot_idle_time; | |
304 | ||
ea25da48 PV |
305 | /* bit vector: a 1 for each seeky requests in history */ |
306 | u32 seek_history; | |
307 | ||
308 | /* node for the device's burst list */ | |
309 | struct hlist_node burst_list_node; | |
310 | ||
311 | /* position of the last request enqueued */ | |
312 | sector_t last_request_pos; | |
313 | ||
314 | /* Number of consecutive pairs of request completion and | |
315 | * arrival, such that the queue becomes idle after the | |
316 | * completion, but the next request arrives within an idle | |
317 | * time slice; used only if the queue's IO_bound flag has been | |
318 | * cleared. | |
319 | */ | |
320 | unsigned int requests_within_timer; | |
321 | ||
322 | /* pid of the process owning the queue, used for logging purposes */ | |
323 | pid_t pid; | |
324 | ||
325 | /* | |
326 | * Pointer to the bfq_io_cq owning the bfq_queue, set to %NULL | |
327 | * if the queue is shared. | |
328 | */ | |
329 | struct bfq_io_cq *bic; | |
330 | ||
331 | /* current maximum weight-raising time for this queue */ | |
332 | unsigned long wr_cur_max_time; | |
333 | /* | |
334 | * Minimum time instant such that, only if a new request is | |
335 | * enqueued after this time instant in an idle @bfq_queue with | |
336 | * no outstanding requests, then the task associated with the | |
337 | * queue it is deemed as soft real-time (see the comments on | |
338 | * the function bfq_bfqq_softrt_next_start()) | |
339 | */ | |
340 | unsigned long soft_rt_next_start; | |
341 | /* | |
342 | * Start time of the current weight-raising period if | |
343 | * the @bfq-queue is being weight-raised, otherwise | |
344 | * finish time of the last weight-raising period. | |
345 | */ | |
346 | unsigned long last_wr_start_finish; | |
347 | /* factor by which the weight of this queue is multiplied */ | |
348 | unsigned int wr_coeff; | |
349 | /* | |
350 | * Time of the last transition of the @bfq_queue from idle to | |
351 | * backlogged. | |
352 | */ | |
353 | unsigned long last_idle_bklogged; | |
354 | /* | |
355 | * Cumulative service received from the @bfq_queue since the | |
356 | * last transition from idle to backlogged. | |
357 | */ | |
358 | unsigned long service_from_backlogged; | |
8a8747dc PV |
359 | /* |
360 | * Cumulative service received from the @bfq_queue since its | |
361 | * last transition to weight-raised state. | |
362 | */ | |
363 | unsigned long service_from_wr; | |
ea25da48 PV |
364 | |
365 | /* | |
366 | * Value of wr start time when switching to soft rt | |
367 | */ | |
368 | unsigned long wr_start_at_switch_to_srt; | |
369 | ||
370 | unsigned long split_time; /* time of last split */ | |
7b8fa3b9 PV |
371 | |
372 | unsigned long first_IO_time; /* time of first I/O for this queue */ | |
d0edc247 | 373 | |
430a67f9 PV |
374 | unsigned long creation_time; /* when this queue is created */ |
375 | ||
d0edc247 PV |
376 | /* max service rate measured so far */ |
377 | u32 max_service_rate; | |
13a857a4 PV |
378 | |
379 | /* | |
380 | * Pointer to the waker queue for this queue, i.e., to the | |
381 | * queue Q such that this queue happens to get new I/O right | |
382 | * after some I/O request of Q is completed. For details, see | |
383 | * the comments on the choice of the queue for injection in | |
384 | * bfq_select_queue(). | |
385 | */ | |
386 | struct bfq_queue *waker_bfqq; | |
71217df3 PV |
387 | /* pointer to the curr. tentative waker queue, see bfq_check_waker() */ |
388 | struct bfq_queue *tentative_waker_bfqq; | |
389 | /* number of times the same tentative waker has been detected */ | |
390 | unsigned int num_waker_detections; | |
1f18b700 JK |
391 | /* time when we started considering this waker */ |
392 | u64 waker_detection_started; | |
71217df3 | 393 | |
13a857a4 PV |
394 | /* node for woken_list, see below */ |
395 | struct hlist_node woken_list_node; | |
396 | /* | |
397 | * Head of the list of the woken queues for this queue, i.e., | |
398 | * of the list of the queues for which this queue is a waker | |
399 | * queue. This list is used to reset the waker_bfqq pointer in | |
400 | * the woken queues when this queue exits. | |
401 | */ | |
402 | struct hlist_head woken_list; | |
ea25da48 PV |
403 | }; |
404 | ||
405 | /** | |
406 | * struct bfq_io_cq - per (request_queue, io_context) structure. | |
407 | */ | |
408 | struct bfq_io_cq { | |
409 | /* associated io_cq structure */ | |
410 | struct io_cq icq; /* must be the first member */ | |
411 | /* array of two process queues, the sync and the async */ | |
412 | struct bfq_queue *bfqq[2]; | |
413 | /* per (request_queue, blkcg) ioprio */ | |
414 | int ioprio; | |
415 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
416 | uint64_t blkcg_serial_nr; /* the current blkcg serial */ | |
417 | #endif | |
418 | /* | |
d5be3fef PV |
419 | * Snapshot of the has_short_time flag before merging; taken |
420 | * to remember its value while the queue is merged, so as to | |
421 | * be able to restore it in case of split. | |
ea25da48 | 422 | */ |
d5be3fef | 423 | bool saved_has_short_ttime; |
ea25da48 PV |
424 | /* |
425 | * Same purpose as the previous two fields for the I/O bound | |
426 | * classification of a queue. | |
427 | */ | |
428 | bool saved_IO_bound; | |
429 | ||
eb2fd80f PV |
430 | u64 saved_io_start_time; |
431 | u64 saved_tot_idle_time; | |
432 | ||
ea25da48 PV |
433 | /* |
434 | * Same purpose as the previous fields for the value of the | |
435 | * field keeping the queue's belonging to a large burst | |
436 | */ | |
437 | bool saved_in_large_burst; | |
438 | /* | |
439 | * True if the queue belonged to a burst list before its merge | |
440 | * with another cooperating queue. | |
441 | */ | |
442 | bool was_in_burst_list; | |
443 | ||
fffca087 FP |
444 | /* |
445 | * Save the weight when a merge occurs, to be able | |
446 | * to restore it in case of split. If the weight is not | |
447 | * correctly resumed when the queue is recycled, | |
448 | * then the weight of the recycled queue could differ | |
449 | * from the weight of the original queue. | |
450 | */ | |
451 | unsigned int saved_weight; | |
452 | ||
ea25da48 PV |
453 | /* |
454 | * Similar to previous fields: save wr information. | |
455 | */ | |
456 | unsigned long saved_wr_coeff; | |
457 | unsigned long saved_last_wr_start_finish; | |
e673914d | 458 | unsigned long saved_service_from_wr; |
ea25da48 PV |
459 | unsigned long saved_wr_start_at_switch_to_srt; |
460 | unsigned int saved_wr_cur_max_time; | |
461 | struct bfq_ttime saved_ttime; | |
5a5436b9 PV |
462 | |
463 | /* Save also injection state */ | |
464 | u64 saved_last_serv_time_ns; | |
465 | unsigned int saved_inject_limit; | |
466 | unsigned long saved_decrease_time_jif; | |
430a67f9 PV |
467 | |
468 | /* candidate queue for a stable merge (due to close creation time) */ | |
469 | struct bfq_queue *stable_merge_bfqq; | |
470 | ||
471 | bool stably_merged; /* non splittable if true */ | |
ea25da48 PV |
472 | }; |
473 | ||
ea25da48 PV |
474 | /** |
475 | * struct bfq_data - per-device data structure. | |
476 | * | |
477 | * All the fields are protected by @lock. | |
478 | */ | |
479 | struct bfq_data { | |
480 | /* device request queue */ | |
481 | struct request_queue *queue; | |
482 | /* dispatch queue */ | |
483 | struct list_head dispatch; | |
484 | ||
485 | /* root bfq_group for the device */ | |
486 | struct bfq_group *root_group; | |
487 | ||
488 | /* | |
489 | * rbtree of weight counters of @bfq_queues, sorted by | |
490 | * weight. Used to keep track of whether all @bfq_queues have | |
491 | * the same weight. The tree contains one counter for each | |
492 | * distinct weight associated to some active and not | |
493 | * weight-raised @bfq_queue (see the comments to the functions | |
494 | * bfq_weights_tree_[add|remove] for further details). | |
495 | */ | |
fb53ac6c | 496 | struct rb_root_cached queue_weights_tree; |
ba7aeae5 | 497 | |
ea25da48 | 498 | /* |
ba7aeae5 PV |
499 | * Number of groups with at least one descendant process that |
500 | * has at least one request waiting for completion. Note that | |
501 | * this accounts for also requests already dispatched, but not | |
502 | * yet completed. Therefore this number of groups may differ | |
503 | * (be larger) than the number of active groups, as a group is | |
504 | * considered active only if its corresponding entity has | |
505 | * descendant queues with at least one request queued. This | |
506 | * number is used to decide whether a scenario is symmetric. | |
507 | * For a detailed explanation see comments on the computation | |
508 | * of the variable asymmetric_scenario in the function | |
509 | * bfq_better_to_idle(). | |
510 | * | |
511 | * However, it is hard to compute this number exactly, for | |
512 | * groups with multiple descendant processes. Consider a group | |
513 | * that is inactive, i.e., that has no descendant process with | |
514 | * pending I/O inside BFQ queues. Then suppose that | |
515 | * num_groups_with_pending_reqs is still accounting for this | |
516 | * group, because the group has descendant processes with some | |
517 | * I/O request still in flight. num_groups_with_pending_reqs | |
518 | * should be decremented when the in-flight request of the | |
519 | * last descendant process is finally completed (assuming that | |
520 | * nothing else has changed for the group in the meantime, in | |
521 | * terms of composition of the group and active/inactive state of child | |
522 | * groups and processes). To accomplish this, an additional | |
523 | * pending-request counter must be added to entities, and must | |
524 | * be updated correctly. To avoid this additional field and operations, | |
525 | * we resort to the following tradeoff between simplicity and | |
526 | * accuracy: for an inactive group that is still counted in | |
527 | * num_groups_with_pending_reqs, we decrement | |
528 | * num_groups_with_pending_reqs when the first descendant | |
529 | * process of the group remains with no request waiting for | |
530 | * completion. | |
531 | * | |
532 | * Even this simpler decrement strategy requires a little | |
533 | * carefulness: to avoid multiple decrements, we flag a group, | |
534 | * more precisely an entity representing a group, as still | |
535 | * counted in num_groups_with_pending_reqs when it becomes | |
536 | * inactive. Then, when the first descendant queue of the | |
537 | * entity remains with no request waiting for completion, | |
538 | * num_groups_with_pending_reqs is decremented, and this flag | |
539 | * is reset. After this flag is reset for the entity, | |
540 | * num_groups_with_pending_reqs won't be decremented any | |
541 | * longer in case a new descendant queue of the entity remains | |
542 | * with no request waiting for completion. | |
ea25da48 | 543 | */ |
ba7aeae5 | 544 | unsigned int num_groups_with_pending_reqs; |
ea25da48 PV |
545 | |
546 | /* | |
73d58118 PV |
547 | * Per-class (RT, BE, IDLE) number of bfq_queues containing |
548 | * requests (including the queue in service, even if it is | |
549 | * idling). | |
ea25da48 | 550 | */ |
73d58118 | 551 | unsigned int busy_queues[3]; |
ea25da48 PV |
552 | /* number of weight-raised busy @bfq_queues */ |
553 | int wr_busy_queues; | |
554 | /* number of queued requests */ | |
555 | int queued; | |
556 | /* number of requests dispatched and waiting for completion */ | |
557 | int rq_in_driver; | |
558 | ||
8cacc5ab PV |
559 | /* true if the device is non rotational and performs queueing */ |
560 | bool nonrot_with_queueing; | |
561 | ||
ea25da48 PV |
562 | /* |
563 | * Maximum number of requests in driver in the last | |
564 | * @hw_tag_samples completed requests. | |
565 | */ | |
566 | int max_rq_in_driver; | |
567 | /* number of samples used to calculate hw_tag */ | |
568 | int hw_tag_samples; | |
569 | /* flag set to one if the driver is showing a queueing behavior */ | |
570 | int hw_tag; | |
571 | ||
572 | /* number of budgets assigned */ | |
573 | int budgets_assigned; | |
574 | ||
575 | /* | |
576 | * Timer set when idling (waiting) for the next request from | |
577 | * the queue in service. | |
578 | */ | |
579 | struct hrtimer idle_slice_timer; | |
580 | ||
581 | /* bfq_queue in service */ | |
582 | struct bfq_queue *in_service_queue; | |
583 | ||
584 | /* on-disk position of the last served request */ | |
585 | sector_t last_position; | |
586 | ||
058fdecc PV |
587 | /* position of the last served request for the in-service queue */ |
588 | sector_t in_serv_last_pos; | |
589 | ||
ea25da48 PV |
590 | /* time of last request completion (ns) */ |
591 | u64 last_completion; | |
592 | ||
13a857a4 PV |
593 | /* bfqq owning the last completed rq */ |
594 | struct bfq_queue *last_completed_rq_bfqq; | |
595 | ||
430a67f9 PV |
596 | /* last bfqq created, among those in the root group */ |
597 | struct bfq_queue *last_bfqq_created; | |
598 | ||
2341d662 PV |
599 | /* time of last transition from empty to non-empty (ns) */ |
600 | u64 last_empty_occupied_ns; | |
601 | ||
602 | /* | |
603 | * Flag set to activate the sampling of the total service time | |
604 | * of a just-arrived first I/O request (see | |
605 | * bfq_update_inject_limit()). This will cause the setting of | |
606 | * waited_rq when the request is finally dispatched. | |
607 | */ | |
608 | bool wait_dispatch; | |
609 | /* | |
610 | * If set, then bfq_update_inject_limit() is invoked when | |
611 | * waited_rq is eventually completed. | |
612 | */ | |
613 | struct request *waited_rq; | |
614 | /* | |
615 | * True if some request has been injected during the last service hole. | |
616 | */ | |
617 | bool rqs_injected; | |
618 | ||
ea25da48 PV |
619 | /* time of first rq dispatch in current observation interval (ns) */ |
620 | u64 first_dispatch; | |
621 | /* time of last rq dispatch in current observation interval (ns) */ | |
622 | u64 last_dispatch; | |
623 | ||
624 | /* beginning of the last budget */ | |
625 | ktime_t last_budget_start; | |
626 | /* beginning of the last idle slice */ | |
627 | ktime_t last_idling_start; | |
2341d662 | 628 | unsigned long last_idling_start_jiffies; |
ea25da48 PV |
629 | |
630 | /* number of samples in current observation interval */ | |
631 | int peak_rate_samples; | |
632 | /* num of samples of seq dispatches in current observation interval */ | |
633 | u32 sequential_samples; | |
634 | /* total num of sectors transferred in current observation interval */ | |
635 | u64 tot_sectors_dispatched; | |
636 | /* max rq size seen during current observation interval (sectors) */ | |
637 | u32 last_rq_max_size; | |
638 | /* time elapsed from first dispatch in current observ. interval (us) */ | |
639 | u64 delta_from_first; | |
640 | /* | |
641 | * Current estimate of the device peak rate, measured in | |
bc56e2ca | 642 | * [(sectors/usec) / 2^BFQ_RATE_SHIFT]. The left-shift by |
ea25da48 PV |
643 | * BFQ_RATE_SHIFT is performed to increase precision in |
644 | * fixed-point calculations. | |
645 | */ | |
646 | u32 peak_rate; | |
647 | ||
648 | /* maximum budget allotted to a bfq_queue before rescheduling */ | |
649 | int bfq_max_budget; | |
650 | ||
651 | /* list of all the bfq_queues active on the device */ | |
652 | struct list_head active_list; | |
653 | /* list of all the bfq_queues idle on the device */ | |
654 | struct list_head idle_list; | |
655 | ||
656 | /* | |
657 | * Timeout for async/sync requests; when it fires, requests | |
658 | * are served in fifo order. | |
659 | */ | |
660 | u64 bfq_fifo_expire[2]; | |
661 | /* weight of backward seeks wrt forward ones */ | |
662 | unsigned int bfq_back_penalty; | |
663 | /* maximum allowed backward seek */ | |
664 | unsigned int bfq_back_max; | |
665 | /* maximum idling time */ | |
666 | u32 bfq_slice_idle; | |
667 | ||
668 | /* user-configured max budget value (0 for auto-tuning) */ | |
669 | int bfq_user_max_budget; | |
670 | /* | |
671 | * Timeout for bfq_queues to consume their budget; used to | |
672 | * prevent seeky queues from imposing long latencies to | |
673 | * sequential or quasi-sequential ones (this also implies that | |
674 | * seeky queues cannot receive guarantees in the service | |
675 | * domain; after a timeout they are charged for the time they | |
676 | * have been in service, to preserve fairness among them, but | |
677 | * without service-domain guarantees). | |
678 | */ | |
679 | unsigned int bfq_timeout; | |
680 | ||
ea25da48 PV |
681 | /* |
682 | * Force device idling whenever needed to provide accurate | |
683 | * service guarantees, without caring about throughput | |
684 | * issues. CAVEAT: this may even increase latencies, in case | |
685 | * of useless idling for processes that did stop doing I/O. | |
686 | */ | |
687 | bool strict_guarantees; | |
688 | ||
689 | /* | |
690 | * Last time at which a queue entered the current burst of | |
691 | * queues being activated shortly after each other; for more | |
692 | * details about this and the following parameters related to | |
693 | * a burst of activations, see the comments on the function | |
694 | * bfq_handle_burst. | |
695 | */ | |
696 | unsigned long last_ins_in_burst; | |
697 | /* | |
698 | * Reference time interval used to decide whether a queue has | |
699 | * been activated shortly after @last_ins_in_burst. | |
700 | */ | |
701 | unsigned long bfq_burst_interval; | |
702 | /* number of queues in the current burst of queue activations */ | |
703 | int burst_size; | |
704 | ||
705 | /* common parent entity for the queues in the burst */ | |
706 | struct bfq_entity *burst_parent_entity; | |
707 | /* Maximum burst size above which the current queue-activation | |
708 | * burst is deemed as 'large'. | |
709 | */ | |
710 | unsigned long bfq_large_burst_thresh; | |
711 | /* true if a large queue-activation burst is in progress */ | |
712 | bool large_burst; | |
713 | /* | |
714 | * Head of the burst list (as for the above fields, more | |
715 | * details in the comments on the function bfq_handle_burst). | |
716 | */ | |
717 | struct hlist_head burst_list; | |
718 | ||
719 | /* if set to true, low-latency heuristics are enabled */ | |
720 | bool low_latency; | |
721 | /* | |
722 | * Maximum factor by which the weight of a weight-raised queue | |
723 | * is multiplied. | |
724 | */ | |
725 | unsigned int bfq_wr_coeff; | |
726 | /* maximum duration of a weight-raising period (jiffies) */ | |
727 | unsigned int bfq_wr_max_time; | |
728 | ||
729 | /* Maximum weight-raising duration for soft real-time processes */ | |
730 | unsigned int bfq_wr_rt_max_time; | |
731 | /* | |
732 | * Minimum idle period after which weight-raising may be | |
733 | * reactivated for a queue (in jiffies). | |
734 | */ | |
735 | unsigned int bfq_wr_min_idle_time; | |
736 | /* | |
737 | * Minimum period between request arrivals after which | |
738 | * weight-raising may be reactivated for an already busy async | |
739 | * queue (in jiffies). | |
740 | */ | |
741 | unsigned long bfq_wr_min_inter_arr_async; | |
742 | ||
743 | /* Max service-rate for a soft real-time queue, in sectors/sec */ | |
744 | unsigned int bfq_wr_max_softrt_rate; | |
745 | /* | |
e24f1c24 PV |
746 | * Cached value of the product ref_rate*ref_wr_duration, used |
747 | * for computing the maximum duration of weight raising | |
748 | * automatically. | |
ea25da48 | 749 | */ |
e24f1c24 | 750 | u64 rate_dur_prod; |
ea25da48 PV |
751 | |
752 | /* fallback dummy bfqq for extreme OOM conditions */ | |
753 | struct bfq_queue oom_bfqq; | |
754 | ||
755 | spinlock_t lock; | |
756 | ||
757 | /* | |
758 | * bic associated with the task issuing current bio for | |
759 | * merging. This and the next field are used as a support to | |
760 | * be able to perform the bic lookup, needed by bio-merge | |
761 | * functions, before the scheduler lock is taken, and thus | |
762 | * avoid taking the request-queue lock while the scheduler | |
763 | * lock is being held. | |
764 | */ | |
765 | struct bfq_io_cq *bio_bic; | |
766 | /* bfqq associated with the task issuing current bio for merging */ | |
767 | struct bfq_queue *bio_bfqq; | |
a52a69ea | 768 | |
a52a69ea PV |
769 | /* |
770 | * Depth limits used in bfq_limit_depth (see comments on the | |
771 | * function) | |
772 | */ | |
773 | unsigned int word_depths[2][2]; | |
44dfa279 | 774 | unsigned int full_depth_shift; |
ea25da48 PV |
775 | }; |
776 | ||
777 | enum bfqq_state_flags { | |
778 | BFQQF_just_created = 0, /* queue just allocated */ | |
779 | BFQQF_busy, /* has requests or is in service */ | |
780 | BFQQF_wait_request, /* waiting for a request */ | |
781 | BFQQF_non_blocking_wait_rq, /* | |
782 | * waiting for a request | |
783 | * without idling the device | |
784 | */ | |
785 | BFQQF_fifo_expire, /* FIFO checked in this slice */ | |
d5be3fef | 786 | BFQQF_has_short_ttime, /* queue has a short think time */ |
ea25da48 PV |
787 | BFQQF_sync, /* synchronous queue */ |
788 | BFQQF_IO_bound, /* | |
789 | * bfqq has timed-out at least once | |
790 | * having consumed at most 2/10 of | |
791 | * its budget | |
792 | */ | |
793 | BFQQF_in_large_burst, /* | |
794 | * bfqq activated in a large burst, | |
795 | * see comments to bfq_handle_burst. | |
796 | */ | |
797 | BFQQF_softrt_update, /* | |
798 | * may need softrt-next-start | |
799 | * update | |
800 | */ | |
801 | BFQQF_coop, /* bfqq is shared */ | |
13a857a4 | 802 | BFQQF_split_coop, /* shared bfqq will be split */ |
ea25da48 PV |
803 | }; |
804 | ||
805 | #define BFQ_BFQQ_FNS(name) \ | |
806 | void bfq_mark_bfqq_##name(struct bfq_queue *bfqq); \ | |
807 | void bfq_clear_bfqq_##name(struct bfq_queue *bfqq); \ | |
808 | int bfq_bfqq_##name(const struct bfq_queue *bfqq); | |
809 | ||
810 | BFQ_BFQQ_FNS(just_created); | |
811 | BFQ_BFQQ_FNS(busy); | |
812 | BFQ_BFQQ_FNS(wait_request); | |
813 | BFQ_BFQQ_FNS(non_blocking_wait_rq); | |
814 | BFQ_BFQQ_FNS(fifo_expire); | |
d5be3fef | 815 | BFQ_BFQQ_FNS(has_short_ttime); |
ea25da48 PV |
816 | BFQ_BFQQ_FNS(sync); |
817 | BFQ_BFQQ_FNS(IO_bound); | |
818 | BFQ_BFQQ_FNS(in_large_burst); | |
819 | BFQ_BFQQ_FNS(coop); | |
820 | BFQ_BFQQ_FNS(split_coop); | |
821 | BFQ_BFQQ_FNS(softrt_update); | |
822 | #undef BFQ_BFQQ_FNS | |
823 | ||
824 | /* Expiration reasons. */ | |
825 | enum bfqq_expiration { | |
826 | BFQQE_TOO_IDLE = 0, /* | |
827 | * queue has been idling for | |
828 | * too long | |
829 | */ | |
830 | BFQQE_BUDGET_TIMEOUT, /* budget took too long to be used */ | |
831 | BFQQE_BUDGET_EXHAUSTED, /* budget consumed */ | |
832 | BFQQE_NO_MORE_REQUESTS, /* the queue has no more requests */ | |
833 | BFQQE_PREEMPTED /* preemption in progress */ | |
834 | }; | |
835 | ||
c0ce79dc CH |
836 | struct bfq_stat { |
837 | struct percpu_counter cpu_cnt; | |
838 | atomic64_t aux_cnt; | |
839 | }; | |
840 | ||
ea25da48 | 841 | struct bfqg_stats { |
fd41e603 TH |
842 | /* basic stats */ |
843 | struct blkg_rwstat bytes; | |
844 | struct blkg_rwstat ios; | |
8060c47b | 845 | #ifdef CONFIG_BFQ_CGROUP_DEBUG |
ea25da48 PV |
846 | /* number of ios merged */ |
847 | struct blkg_rwstat merged; | |
848 | /* total time spent on device in ns, may not be accurate w/ queueing */ | |
849 | struct blkg_rwstat service_time; | |
850 | /* total time spent waiting in scheduler queue in ns */ | |
851 | struct blkg_rwstat wait_time; | |
852 | /* number of IOs queued up */ | |
853 | struct blkg_rwstat queued; | |
854 | /* total disk time and nr sectors dispatched by this group */ | |
c0ce79dc | 855 | struct bfq_stat time; |
ea25da48 | 856 | /* sum of number of ios queued across all samples */ |
c0ce79dc | 857 | struct bfq_stat avg_queue_size_sum; |
ea25da48 | 858 | /* count of samples taken for average */ |
c0ce79dc | 859 | struct bfq_stat avg_queue_size_samples; |
ea25da48 | 860 | /* how many times this group has been removed from service tree */ |
c0ce79dc | 861 | struct bfq_stat dequeue; |
ea25da48 | 862 | /* total time spent waiting for it to be assigned a timeslice. */ |
c0ce79dc | 863 | struct bfq_stat group_wait_time; |
ea25da48 | 864 | /* time spent idling for this blkcg_gq */ |
c0ce79dc | 865 | struct bfq_stat idle_time; |
ea25da48 | 866 | /* total time with empty current active q with other requests queued */ |
c0ce79dc | 867 | struct bfq_stat empty_time; |
ea25da48 | 868 | /* fields after this shouldn't be cleared on stat reset */ |
84c7afce OS |
869 | u64 start_group_wait_time; |
870 | u64 start_idle_time; | |
871 | u64 start_empty_time; | |
ea25da48 | 872 | uint16_t flags; |
8060c47b | 873 | #endif /* CONFIG_BFQ_CGROUP_DEBUG */ |
ea25da48 PV |
874 | }; |
875 | ||
876 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
877 | ||
878 | /* | |
879 | * struct bfq_group_data - per-blkcg storage for the blkio subsystem. | |
880 | * | |
881 | * @ps: @blkcg_policy_storage that this structure inherits | |
882 | * @weight: weight of the bfq_group | |
883 | */ | |
884 | struct bfq_group_data { | |
885 | /* must be the first member */ | |
886 | struct blkcg_policy_data pd; | |
887 | ||
888 | unsigned int weight; | |
889 | }; | |
890 | ||
891 | /** | |
892 | * struct bfq_group - per (device, cgroup) data structure. | |
893 | * @entity: schedulable entity to insert into the parent group sched_data. | |
894 | * @sched_data: own sched_data, to contain child entities (they may be | |
895 | * both bfq_queues and bfq_groups). | |
896 | * @bfqd: the bfq_data for the device this group acts upon. | |
897 | * @async_bfqq: array of async queues for all the tasks belonging to | |
898 | * the group, one queue per ioprio value per ioprio_class, | |
899 | * except for the idle class that has only one queue. | |
900 | * @async_idle_bfqq: async queue for the idle class (ioprio is ignored). | |
901 | * @my_entity: pointer to @entity, %NULL for the toplevel group; used | |
902 | * to avoid too many special cases during group creation/ | |
903 | * migration. | |
904 | * @stats: stats for this bfqg. | |
905 | * @active_entities: number of active entities belonging to the group; | |
906 | * unused for the root group. Used to know whether there | |
907 | * are groups with more than one active @bfq_entity | |
908 | * (see the comments to the function | |
909 | * bfq_bfqq_may_idle()). | |
910 | * @rq_pos_tree: rbtree sorted by next_request position, used when | |
911 | * determining if two or more queues have interleaving | |
912 | * requests (see bfq_find_close_cooperator()). | |
913 | * | |
914 | * Each (device, cgroup) pair has its own bfq_group, i.e., for each cgroup | |
915 | * there is a set of bfq_groups, each one collecting the lower-level | |
916 | * entities belonging to the group that are acting on the same device. | |
917 | * | |
918 | * Locking works as follows: | |
919 | * o @bfqd is protected by the queue lock, RCU is used to access it | |
920 | * from the readers. | |
921 | * o All the other fields are protected by the @bfqd queue lock. | |
922 | */ | |
923 | struct bfq_group { | |
924 | /* must be the first member */ | |
925 | struct blkg_policy_data pd; | |
926 | ||
8f9bebc3 PV |
927 | /* cached path for this blkg (see comments in bfq_bic_update_cgroup) */ |
928 | char blkg_path[128]; | |
929 | ||
930 | /* reference counter (see comments in bfq_bic_update_cgroup) */ | |
931 | int ref; | |
932 | ||
ea25da48 PV |
933 | struct bfq_entity entity; |
934 | struct bfq_sched_data sched_data; | |
935 | ||
936 | void *bfqd; | |
937 | ||
202bc942 | 938 | struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS]; |
ea25da48 PV |
939 | struct bfq_queue *async_idle_bfqq; |
940 | ||
941 | struct bfq_entity *my_entity; | |
942 | ||
943 | int active_entities; | |
944 | ||
945 | struct rb_root rq_pos_tree; | |
946 | ||
947 | struct bfqg_stats stats; | |
948 | }; | |
949 | ||
950 | #else | |
951 | struct bfq_group { | |
4d8340d0 | 952 | struct bfq_entity entity; |
ea25da48 PV |
953 | struct bfq_sched_data sched_data; |
954 | ||
202bc942 | 955 | struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS]; |
ea25da48 PV |
956 | struct bfq_queue *async_idle_bfqq; |
957 | ||
958 | struct rb_root rq_pos_tree; | |
959 | }; | |
960 | #endif | |
961 | ||
ea25da48 PV |
962 | /* --------------- main algorithm interface ----------------- */ |
963 | ||
964 | #define BFQ_SERVICE_TREE_INIT ((struct bfq_service_tree) \ | |
965 | { RB_ROOT, RB_ROOT, NULL, NULL, 0, 0 }) | |
966 | ||
967 | extern const int bfq_timeout; | |
968 | ||
969 | struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync); | |
970 | void bic_set_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq, bool is_sync); | |
971 | struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic); | |
ea25da48 | 972 | void bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq); |
2d29c9f8 | 973 | void bfq_weights_tree_add(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
fb53ac6c | 974 | struct rb_root_cached *root); |
0471559c | 975 | void __bfq_weights_tree_remove(struct bfq_data *bfqd, |
2d29c9f8 | 976 | struct bfq_queue *bfqq, |
fb53ac6c | 977 | struct rb_root_cached *root); |
0471559c PV |
978 | void bfq_weights_tree_remove(struct bfq_data *bfqd, |
979 | struct bfq_queue *bfqq); | |
ea25da48 PV |
980 | void bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
981 | bool compensate, enum bfqq_expiration reason); | |
982 | void bfq_put_queue(struct bfq_queue *bfqq); | |
983 | void bfq_end_wr_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg); | |
c8997736 | 984 | void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq); |
ea25da48 PV |
985 | void bfq_schedule_dispatch(struct bfq_data *bfqd); |
986 | void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg); | |
987 | ||
988 | /* ------------ end of main algorithm interface -------------- */ | |
989 | ||
990 | /* ---------------- cgroups-support interface ---------------- */ | |
991 | ||
fd41e603 | 992 | void bfqg_stats_update_legacy_io(struct request_queue *q, struct request *rq); |
ea25da48 PV |
993 | void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq, |
994 | unsigned int op); | |
995 | void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op); | |
996 | void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op); | |
84c7afce OS |
997 | void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns, |
998 | u64 io_start_time_ns, unsigned int op); | |
ea25da48 PV |
999 | void bfqg_stats_update_dequeue(struct bfq_group *bfqg); |
1000 | void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg); | |
1001 | void bfqg_stats_update_idle_time(struct bfq_group *bfqg); | |
1002 | void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg); | |
1003 | void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg); | |
1004 | void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, | |
1005 | struct bfq_group *bfqg); | |
1006 | ||
1007 | void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg); | |
1008 | void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio); | |
1009 | void bfq_end_wr_async(struct bfq_data *bfqd); | |
1010 | struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, | |
1011 | struct blkcg *blkcg); | |
1012 | struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg); | |
1013 | struct bfq_group *bfqq_group(struct bfq_queue *bfqq); | |
1014 | struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node); | |
8f9bebc3 | 1015 | void bfqg_and_blkg_put(struct bfq_group *bfqg); |
ea25da48 PV |
1016 | |
1017 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
659b3394 JA |
1018 | extern struct cftype bfq_blkcg_legacy_files[]; |
1019 | extern struct cftype bfq_blkg_files[]; | |
ea25da48 PV |
1020 | extern struct blkcg_policy blkcg_policy_bfq; |
1021 | #endif | |
1022 | ||
1023 | /* ------------- end of cgroups-support interface ------------- */ | |
1024 | ||
1025 | /* - interface of the internal hierarchical B-WF2Q+ scheduler - */ | |
1026 | ||
1027 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
1028 | /* both next loops stop at one of the child entities of the root group */ | |
1029 | #define for_each_entity(entity) \ | |
1030 | for (; entity ; entity = entity->parent) | |
1031 | ||
1032 | /* | |
1033 | * For each iteration, compute parent in advance, so as to be safe if | |
1034 | * entity is deallocated during the iteration. Such a deallocation may | |
1035 | * happen as a consequence of a bfq_put_queue that frees the bfq_queue | |
1036 | * containing entity. | |
1037 | */ | |
1038 | #define for_each_entity_safe(entity, parent) \ | |
1039 | for (; entity && ({ parent = entity->parent; 1; }); entity = parent) | |
1040 | ||
1041 | #else /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1042 | /* | |
1043 | * Next two macros are fake loops when cgroups support is not | |
1044 | * enabled. I fact, in such a case, there is only one level to go up | |
1045 | * (to reach the root group). | |
1046 | */ | |
1047 | #define for_each_entity(entity) \ | |
1048 | for (; entity ; entity = NULL) | |
1049 | ||
1050 | #define for_each_entity_safe(entity, parent) \ | |
1051 | for (parent = NULL; entity ; entity = parent) | |
1052 | #endif /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1053 | ||
1054 | struct bfq_group *bfq_bfqq_to_bfqg(struct bfq_queue *bfqq); | |
1055 | struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity); | |
73d58118 | 1056 | unsigned int bfq_tot_busy_queues(struct bfq_data *bfqd); |
ea25da48 PV |
1057 | struct bfq_service_tree *bfq_entity_service_tree(struct bfq_entity *entity); |
1058 | struct bfq_entity *bfq_entity_of(struct rb_node *node); | |
1059 | unsigned short bfq_ioprio_to_weight(int ioprio); | |
1060 | void bfq_put_idle_entity(struct bfq_service_tree *st, | |
1061 | struct bfq_entity *entity); | |
1062 | struct bfq_service_tree * | |
1063 | __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st, | |
431b17f9 PV |
1064 | struct bfq_entity *entity, |
1065 | bool update_class_too); | |
ea25da48 PV |
1066 | void bfq_bfqq_served(struct bfq_queue *bfqq, int served); |
1067 | void bfq_bfqq_charge_time(struct bfq_data *bfqd, struct bfq_queue *bfqq, | |
1068 | unsigned long time_ms); | |
1069 | bool __bfq_deactivate_entity(struct bfq_entity *entity, | |
1070 | bool ins_into_idle_tree); | |
1071 | bool next_queue_may_preempt(struct bfq_data *bfqd); | |
1072 | struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd); | |
eed47d19 | 1073 | bool __bfq_bfqd_reset_in_service(struct bfq_data *bfqd); |
ea25da48 PV |
1074 | void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1075 | bool ins_into_idle_tree, bool expiration); | |
1076 | void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq); | |
80294c3b PV |
1077 | void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1078 | bool expiration); | |
ea25da48 PV |
1079 | void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1080 | bool expiration); | |
1081 | void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq); | |
1082 | ||
1083 | /* --------------- end of interface of B-WF2Q+ ---------------- */ | |
1084 | ||
1085 | /* Logging facilities. */ | |
582f04e1 | 1086 | static inline void bfq_bfqq_name(struct bfq_queue *bfqq, char *str, int len) |
1e66413c | 1087 | { |
582f04e1 JK |
1088 | char type = bfq_bfqq_sync(bfqq) ? 'S' : 'A'; |
1089 | ||
1090 | if (bfqq->pid != -1) | |
1091 | snprintf(str, len, "bfq%d%c", bfqq->pid, type); | |
1e66413c | 1092 | else |
582f04e1 | 1093 | snprintf(str, len, "bfqSHARED-%c", type); |
1e66413c FP |
1094 | } |
1095 | ||
ea25da48 PV |
1096 | #ifdef CONFIG_BFQ_GROUP_IOSCHED |
1097 | struct bfq_group *bfqq_group(struct bfq_queue *bfqq); | |
1098 | ||
1099 | #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ | |
582f04e1 | 1100 | char pid_str[MAX_BFQQ_NAME_LENGTH]; \ |
40d47c15 DM |
1101 | if (likely(!blk_trace_note_message_enabled((bfqd)->queue))) \ |
1102 | break; \ | |
582f04e1 | 1103 | bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH); \ |
35fe6d76 SL |
1104 | blk_add_cgroup_trace_msg((bfqd)->queue, \ |
1105 | bfqg_to_blkg(bfqq_group(bfqq))->blkcg, \ | |
582f04e1 | 1106 | "%s " fmt, pid_str, ##args); \ |
ea25da48 PV |
1107 | } while (0) |
1108 | ||
35fe6d76 SL |
1109 | #define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do { \ |
1110 | blk_add_cgroup_trace_msg((bfqd)->queue, \ | |
1111 | bfqg_to_blkg(bfqg)->blkcg, fmt, ##args); \ | |
1112 | } while (0) | |
ea25da48 PV |
1113 | |
1114 | #else /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1115 | ||
1e66413c | 1116 | #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ |
582f04e1 | 1117 | char pid_str[MAX_BFQQ_NAME_LENGTH]; \ |
40d47c15 DM |
1118 | if (likely(!blk_trace_note_message_enabled((bfqd)->queue))) \ |
1119 | break; \ | |
582f04e1 JK |
1120 | bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH); \ |
1121 | blk_add_trace_msg((bfqd)->queue, "%s " fmt, pid_str, ##args); \ | |
1e66413c | 1122 | } while (0) |
ea25da48 PV |
1123 | #define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do {} while (0) |
1124 | ||
1125 | #endif /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1126 | ||
1127 | #define bfq_log(bfqd, fmt, args...) \ | |
1128 | blk_add_trace_msg((bfqd)->queue, "bfq " fmt, ##args) | |
1129 | ||
1130 | #endif /* _BFQ_H */ |